Jacob yotjngman



5MM/Q8,

(No Model.)

J. YOUNGMAN.

BALANCED SLIDE VALVE.

No. 892578.. Patented Nov. 8, 1888.

mmmuilg.

www

n. Prrsna Phnwumgmpnnr. wnmngnm n. a

lNrTED STATES Artnr rtree,

JACOB YOUNGMAN, OF SUNBURY, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TOJONATHAN M. BASTIAN, OF SAME PLACE.

BALANCED SLIDEHVALVE.

SPECIFICATION forming part of Letters Patent No. 392,578, dated November6, 1888.

l Application filed January Q4, 1888. Serial No. 261,722. (No model.) l

To all whom t may concern: l

Be it known that I, JACOB YoUNGM-AN, a citizen of the United States,residing at Sunbury, in the county of Northumberland and State ofPennsylvania, have invented certain new and useful Improvements inBalanced Slide-Valves for Steam-Eu gines; and I do hereby declare thefollowing to be a full, clear, and

exact description of the invention, such as will 1o enable othersskilled in the art to which it appertains to make and use the same.

This invention relates to valves of that class known as balancedslide-valves;77 and it has for its object to provide a moreperfectly-bal I 5 anced valve of simple and cheap construction whichshall effectually prevent the leakage of steam from the chest to theback of the valve, thus relieving the same of the downwardpressure,which is common in the ordinary D-valve 2o and which is theoccasion of much wear of the valve and seats for the same; and itconsists of the parts and combinations of parts hereinafter describedand claimed.

In the accompanying drawings, forming a e 5 part of thisspeciticatiomFigurel isalongitudinal central section through myimprovedvalve and steamchest; Fig. 2,a vertical crosssection through the same;Fig. 3, a detail view of the valve proper, showing the arrangement ofthe 3o packing-strips; Fig. ll, a detail view of the bearing cap orframe for the valve, and Fig. 5 a perspective view of one .of thepacking`n strips.

Similarlettcrs refer to similar parts through- 7,5 out the several.views.

A, represents a portion of the cylinder' for the piston of an engine,provided with the usual steam-ports, c, and exhaust-port b. On thecylinder the steam-chest B is secured in the 1.o usual or any desiredmanner over the ports c vl1. On the chest is secured a lid, C, having abonnet or arched. head, D, as clearly shown in lliig. 2, in which thebalanceplate E is adj ustably suspended by means of screw-bolts c,passing through the bonnet and into lugs formed on the back of theplate. By this construction of the head D, I secure increased capacityof the chest, as I am enabled to locate the plate E entirely within thearched head.

The valve F is provided with the usual exhaust-cavity, d, but differsfrom all other valves with which Iam familiar in that itis cast hollowor box-shaped, thus providing a chamber,

e, within its walls f, as clearly shown in Fig.

3. At about the center of the upper surface ",5 or top of the wallf, Iinsert short studs or pins g at suitable distances apart, there being,preferably, two pins in each side and end wall.

G represents the metallic packingstrips, havingslots h formed intheirsides correspond- 6o ing to the pins g in number and location, sothat they may be fitted on top ofthe walls with the slots embracing thepins or studs, the slotted sides of the strips being outward. The stripsconstitute an extension of the walls of the valve, but are movablelaterally or inwardly on the tops of said walls. As shown most clearlyiu Fig. 5, these strips taper toward their lower sides, so that they arenarrower than the upper surface of the walls on 7o which they rest.

The object of thus reducing the strips is to obviate the tendency theywould have to hold the overlapping rim or flange m of the bearing cap orrectangular frame II if the two sides were equal, and thus destroy thefreedom of movement which the cap should have. It will also be seen, onreference to Fig. 3, that the side walls of the valve have cleats n castou their inner sides, the object of which is to give 8o clearance forthe tool in dressing said sides to a fit for the downwardly-projectingWalls o of the bearing-cap. rThis cap is `formed of a rectangularframehaving the walls o and rim or overlapping ilange in and a eross-piece,p, provided with a downwardly-extending pin,

r, said cross-piece being located with its upper surface below the topof the cap, so that it cannot form part of the abrasive surface.

A. spring, M, is placed within the chamber '9o c so that it will exertits pressure upwardly against the crosspicce p to raise the bearingcapup against the balanceplate when steam is shut off, and also give thenecessary elasticity to the cap and valve. The spring shown is anordinary fiat bow-spring having a perforation at its center, throughwhich the pin r projects to guide and steady said spring; but it may be,if desired, a spiral spring surrounding the pin. The cap I-I is fittedor is tele- Ioo scoped within the chamber e of the valve, filling thesame closely, and its rim m rests on the strips G and projects outwardlybeyond the same. The bottom of the valve is also provided with flanges son its four sides, as shown. The perforation w in the center of thebottom of the valve is for the purpose of giv ing an outlet to any steamwhich may get back of the valve or in its chamber through theexhaustport.

In operation the steam isadmitted to the chest, and from thence to theports a in the usual manner, and exhausts from the cylinder through portb, and thence to the air or a condenser, as desired. The steam in thechest, however, exerts a powerful lateral pressure on the strips,forcing them in closely against the walls o ofthe bearing-cap, and alsolifting the said bearing-cap up against the balanceplate by the pressurewhich is exerted against the under side of its rim, while at the sametime it exerts a downward pressure on the upper surface of said strips,causing t-hc latter to closely hug the walls of the valve, thus closingthe joint between the walls and strips by the downward pressure and thejoint between the walls o ot' the bearingcap and the strips bythelateral pressure on the latter, and tinally closing thejoint between thebalance-plate and the cap by the upward pressure of the steam ou the rimor flange of said cap, and preventing the admission of live steam to theback of the valve.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination, with the steam-chest having an arched head or lidand a balanceplate adjustably secured within said head, of the valvehaving a chamber formed in its body, the pins rigidly secured to thewalls of said chamber, the metallic strips having slots in their sidesresting on said walls, the rectangular bearing-cap fitted Within saidchamber and having-the overlapping rim, the crosspiece having thedownwardly-projecting pin, and a spring guided and steadied by said pinand bearing against said cross-piece, substantially as described.

2. The combination, in a balanced slidevalve, of the valve having thechamber formed in its body, the cleats formed in the walls of saidchamber, the pins or studs rigidly secured@ in said walls, the metallicpackingstrips having slots formedin their sides, the bearingcap havingthe downwardly-extending walls and projecting rim, the cross-pieceprovided with a downwardly-projecting pin, and the spring located withinsaid chamber and exerting its pressure against said cross piece,substantially as described.

8. The combination, iu a balanced slidevalve, with a suitablesteam-chest and balanceplate, of a valve having a chamber formed in itsbody, the pins rigidly secured in the walls of said chamber, thetapering metallic strips having slots formed in their sides, thebearingcap having the outwardly-projecting rim and downwardly-extendingwalls, the cross-piece having the downwardly-projecting pin, and aspring bearing ou the bottom of said chamber and against saidcross-piece and guided and steadied by said pin, substantially asdescribed.

In testimony whereof I at'x my signature in presence of two witnesses.

JACOB YOUNGMAN.

Witnesses:

NATHANIEL FORD, H. D. MILLER.

